I need a suggestion here , by looking at the subject you would have realized that i am inclined towards this lens..

Yes , but i want to know if this lens is good for wedding / indoor photography.. With F4 , will it fell short ? I have a canon 5d mk3 body , so my assumption is boosting up ISO might get away with low light scenarios , but in practical how good is this lens? I am also thinking of 85mm 1.8 for wedding , being prime , i heard this lens is good for portraits and candid shots , but i'll have to sacrifice the zoom range offered by 24-105 , is it worth ? Coz 85mm 1.8 is less expensive compared to 24-105 and does it make sense in the first place? Pls advise me on this.

I shoot all-primes at weddings, 35/1.4, 50/1.8, 85/1.8, and 135/2 and I *still* need flash if I want to keep a reasonable ISO. Weddings are specialized situations, so I'd suggest specialized lenses. 24-105 is non-specialized, so I don't really recommend it.

No flash at ceremonies, ISO under 2500 and shutters ~1/80th, apertures to suit.

For receptions, my go-to is ISO 1250, f/3.5, 1/60th, and 1/4 power bounced up or slightly backward. Every venue is different but most places I shoot indoors at work right around this for a nice mix of ambient and flash. Change apertures/flash power/ISO to suit.

I have the 24-105 and it is not very good for indoor, non-flash photography. I have had a lot of luck with my EF 50 F/1.4 indoors with no flash. It is an inexpensive (relatively) lens that performs wonderfully. The only down side is that you actually have to use your legs to zoom.